The disclosures of Japanese Patent Application Nos. HEI 11-086216 filed on Mar. 29, 1999, and HEI 11-135770 filed on May 17, 1999 including their specifications, drawings and abstracts are incorporated herein by reference in their entireties.
1. Field of Invention
The present invention relates to a wire winding apparatus and, more particularly, to a wire winding apparatus for producing a coil by winding an element wire, and to a coil producing method.
2. Description of Related Art
A known wire winding apparatus has two rollers that are disposed in a sandwich positional relationship relative to a winding frame to guide an element wire so that the element wire wound on the winding frame in proper alignment is prevented from shifting sideways.
Another wire winding apparatus has been proposed (in, for example, Japanese Patent Application Laid-Open No. SHO 64-43046) which has members for guiding an element wire to be wound. In this apparatus, two guide members are disposed in a sandwich positional relationship relative to a winding frame. When an element wire is wound on the winding frame, the guide members are alternately shifted by one pitch in a direction of the winding process.
However, both the wire winding apparatus described above have a problem of failing to wind an element wire on a winding frame with a high winding density. More specifically, when the winding of an element wire is shifted from one turn to the next turn, a small gap is formed between the turns of the element wire. Each of the aforementioned apparatus guides and holds an element wire wound on the winding frame in proper alignment, but does not guide or hold an xe2x80x9cSxe2x80x9d-curved portion of the element wire that is needed for a turn shift of the winding. Therefore, a gap is formed at the position of a turn shift. Such gaps lead to a reduced number of times that the element wire can be wound, that is, a reduction in the number of turns of a coil to be formed. Employment of such a coil in an appliance (or machine), such as an electric motor, an electric generator or the like, adversely affects the performance of the appliance (or machine).
Accordingly, it is an object of the invention to produce a desired coil at high speed and a low cost. It is another object of the invention to shift an element wire from one turn to the next turn while properly aligning the turns of the element wire. It is still another object to align turn shift portions of an element wire while adopting a simple apparatus construction that does not require replacement of component parts and, therefore, improve the productivity corresponding to omission of an alignment tool replacing time. It is a further object to provide an apparatus capable of accomplishing the aligned winding of a thick rectangular wire on a trapezoidal bobbin or formation of a pyramidal coil with proper alignment, which cannot be accomplished by conventional general-purpose bobbin winding apparatus.
To achieve one or more of the aforementioned and/or other objects, an aspect of the invention provides a wire winding apparatus for forming a coil by winding an element wire. The apparatus includes a winding frame which is rotatable and on which the element wire is wound during rotation of the winding frame. The apparatus also includes an element wire support that is movable in a direction of a rotating axis of the winding frame, and that supports the element wire and applies a predetermined tension to the element wire. The apparatus further includes a turn shift portion shaper that contacts the element wire and forms a turn shift portion in the element wire by utilizing the tension applied to the element wire by the element wire support, when the element wire is shifted from a turn to another turn during winding of the element wire around the winding frame.
The above-described apparatus is capable of aligning turn shift portions of the element wire with good regularity. Since the apparatus forms turn shift portions by utilizing the tension applied to the element wire, the apparatus construction can be simplified. Furthermore, if the turn shift portion shaper in the invention is prepared as an add-on kit, an apparatus according to the invention can be realized easily by improving the element wire supporting device of a general-purpose bobbin winding apparatus through the use of the add-on kit.
In the wire winding apparatus described above, a site of the turn shift portion shaper that contacts the element wire may be movable within a predetermined range of space adjacent to the winding frame. Therefore, when the element wire winding layer is changed, the direction of contact of the turn shift portion shaper with the element wire can be changed, so that there is no need to replace a component part for forming a turn shift portion. As a result, a coil can be produced at high speed and low cost, thereby improving the production efficiency.
Furthermore, the above-described apparatus may further have a construction in which a rotational position of the winding frame is detected and, based on a value detected thereby, the driving of the element wire support and the turn shift portion shaper is controlled. This construction makes it possible to more reliably form a turn shift portion at a proper position and therefore speedily form a coil.